Fix ChromeHeadless CI timeout on macOS

[Copilot]

ChromeHeadless was consistently timing out (3× 60s) on macos-latest in the Karma test run, failing the Node CI check on this PR.

Changes

• karma.config.cjs: Replace ChromeHeadless browser with a ChromeHeadlessNoSandbox custom launcher that passes --no-sandbox and --disable-setuid-sandbox — the standard fix for headless Chrome in containerized/CI environments where the sandbox prevents browser startup.

customLaunchers: {
  ChromeHeadlessNoSandbox: {
    base: 'ChromeHeadless',
    flags: ['--no-sandbox', '--disable-setuid-sandbox'],
  },
},
browsers: ['ChromeHeadlessNoSandbox'],

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[Copilot]

Pull request overview

This PR fixes a CI timeout issue where ChromeHeadless was failing to start on macos-latest GitHub Actions runners due to sandbox restrictions. It replaces the direct ChromeHeadless browser reference with a custom launcher that disables the sandbox, which is the standard fix for headless Chrome in CI environments.

Changes:

• Replace ChromeHeadless with a ChromeHeadlessNoSandbox custom launcher in karma.config.cjs, passing --no-sandbox and --disable-setuid-sandbox flags to allow Chrome to start reliably in CI.

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